What should I do about this:

Parsing nf-test error
Parsed nf-test error
╭────────────────────────────────────────────────────────────────────────────────── nf-test error ───────────────────────────────────────────────────────────────────────────────────╮
│ INFO    2026-09-18 10:36:25 DeflaterFactory libdeflate is available; using libdeflate for DEFLATE compression.                                                                     │
│                                                                                                                                                                                    │
╰────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────╯
Displaying nf-test error
CRITICAL Ran, but found errors:
          - nf-test failed
          - nf-test failed

is that the most recent version of nf-core tools?

it is v.4.1.0

I haven't tried this workaround for your case, but instead of using

alias

I will sometimes write small executable bash wrappers and put them at the start of my PATH environment variable. Ex:

$HOME/.local/bin/singularity

contents:

#!/bin/bash
apptainer "$@"

Then:

export PATH=$HOME/.local/bin/bin:$PATH
chmod +x $HOME/.local/bin/singularity
singularity --version

That's pretty clever